The present invention relates to a vibration control apparatus for a vehicle having an electric motor, and more specifically to such a vibration control apparatus for restraining hunching in torque.
A Published Japanese Patent Application Kokai Publication No. 2001-45613 shows a vibration control apparatus for a vehicle driven by an electric motor.
It is an object of the present invention to provide vibration control apparatus and/or process capable of reducing vibrations reliably in a vehicle powered by an electric motor. Another object is to provide vibration control apparatus and/or process capable of reducing vibrations securely even in a situation in which an accelerator pedal is depressed from a stop state or a deceleration state.
According to one aspect of the present invention, a vibration control apparatus for a vehicle powered by an electric motor (6) comprises: (a) a motor speed sensor to sense an actual motor speed of the electric motor; (b) a first target torque setting section to set a first target torque in accordance with vehicle information on a vehicle operating condition; (c) a motor speed estimating section which includes a filter having a model Gp(s) of a transfer characteristic between a vehicle torque input and a motor speed, and which is arranged to receive a command motor torque and to calculate an estimated motor speed of the electric motor from the command motor torque with the filter; (d) a deviation calculating section determining an input quantity from a deviation of the actual motor speed from the estimated motor speed; (e) a second target torque setting section including a filter having a model H(s)/Gp(s) composed of a transfer characteristic H(s) which is greater than or equal to the model Gp(s) in an order difference between the order of a denominator and the order of a numerator, the second target torque setting section being arranged to receive the input quantity from the deviation calculating section and to calculate, as an output quantity, a second target torque from the input quantity with the filter having the model H(s)/Gp(s); (f) a command torque calculating section to calculate the command motor torque by addition of the first target torque and the second target torque, and to deliver the command motor torque to the motor speed estimating section; and (g) a motor torque controlling section to control the electric motor to bring an actual output torque of the electric motor closer to the command motor torque.
According to another aspect of the present invention, a vibration control apparatus for a vehicle powered by an electric motor comprises: a motor speed calculating section which includes a filter having a desired model Gm(s) of a transfer characteristic between a vehicle torque input and a motor speed, and which is arranged to receive a command motor torque and to calculate a desired motor speed of the electric motor from the command motor torque with the filter; a subtracting section determining a deviation of the actual motor speed from the estimated motor speed; and a second target torque setting section including a filter having a model H(s)/Gp(s) composed of a transfer characteristic H(s) which is greater than or equal to a transfer characteristic Gp(s) in an order difference between the order of a denominator and the order of a numerator, the second target torque setting section being arranged to receive the deviation from the subtracting section and to calculate a second target torque from the deviation with the filter having the model H(s)/Gp(s).
According to still another aspect of the present invention, a vibration control apparatus for a vehicle having a prime mover including an electric motor, the vibration control apparatus comprises: (a) first calculating means for calculating a first target torque in accordance with vehicle information on a vehicle operating condition; (b) second calculating means for calculating a second target torque in accordance with a sensed motor speed by using a torque determining model H(s)/Gp(s) composed of a transfer characteristic H(s) which is greater than a transfer characteristic Gp(s) in an order difference between the order of a denominator and the order of a numerator; (c) third calculating means for calculating a command motor torque from the first target torque and the second target torque; and (d) controlling means for controlling the electric motor to bring an actual output torque of the electric motor closer to the command motor torque.
According to still another aspect of the present invention, a vibration control process for a vehicle having a prime mover including an electric motor, the vibration control process comprises: (a) calculating a first target torque in accordance with vehicle information on a vehicle operating condition; (b) calculating a second target torque from a sensed motor speed of the electric motor, by using a model H(s)/Gp(s) composed of a transfer characteristic H(s) which is greater than or equal to a transfer characteristic Gp(s) in an order difference between the order of a denominator and the order of a numerator; and (c) calculating a command motor torque from the first target torque and the second target torque, to control the electric motor to bring an actual output torque of the electric motor closer to the command motor torque.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.